Eico HF-20 - Listening to Sources; Tone and Loudness Controls

PRELIMINARY!
Be
lure
oil
tube*
are
firmly
seated
In
their
sockets
and
that
the
tube
shteldsare
making
good
contact
with
their
bases.
As
Initial
adjustments,
set
these
controls
as
follows:
LEVEL
at
zero,
LOUDNESS
at
ten,
BASS
at
zero.
Turn the
amplifier
on
by
turning
the
TREBLE
con-
trol
clockwise
from
OFF
and
set It at
zero
Initially.
LISTENING
TO
PHONOGRAPH:
Set the
SELECTOR
to
one of
the
record
equalization
positions
on
the
dial.
Do-
ing
so
automatically
selects
thephonograph
Input
plugged
Into
PHONO
INPUT
1
or
PHONO
INPUT
2. For
help
In
choosing
the
recording
curve
appropriate
to
any
parti-
cular
record,
refer
to
thechart
titled
"RECORD
EQUILh
ZATION
SELECTION".
When
In
doubt
as
to
which
equl
II-
zaflon
Is
most
appropriate,
use
RIAA,
which
Is the
best
compromise
for all
records.
Keep
In
mind
that
while
the
positions
offered
caver
most
recording
curves
likely
to
be
encountered,
additional
separate
and
variable
bass
and
treble
response
adjustments
are
necessary
for
folly
satis-
factory
results.
These may
be
necessary
to
compensate
for the
over-all
characteristics
of
your
audio
system
(In-
cluding
room
acoustics).
Inexact
matching
of
the
actual
recording
characteristic
by any
of
the
equalizations
pro-
vided,
and,
above all,
the
particular
tastes
of
the
listener.
4
LEVEL
&
LOUDNESS
CONTROLS:
Simply
stated,
the
purpose
of the
LOUDNESS
control
Is
to
provide
compen-
sation
for the
Increasing
Inefflctencyof
the
human
ear
In
hearing
bass
and
treble
with
decreasing
volume
level
.
The
LOUDNESS
control,
as It
Is
turned
counter-clockwise
from
maximum
clockwise
rotation,
not
only
decreraes
the
volume
but
Increasingly
emphasizes
the
bass
and treble
according
to the
Fletcher-
Munson
curves
(curves
developed
from a
statistical
study
of
this effect).
An
uncompensated
LEVEL
control
Is
also
provided
to "set"
the
LOUDNESS
control
for
proper
operation
In
any
system,
and
also
for
the
purpose
of
adjusting
the
listening
level
when
going
from
quiet
program
material
to
loud
program
material
or
the
reverse
without
occasioning
a
change
In
the
loudness
compensation.
To
"set"
the
LOUDNESS
control
at
any
time,
perform
these
operations In the order
gjv
^p
to avoid
blasting
or
possible
damage
to
speakers
of
low
power-hand-
ling
capacity:
a)
Turn
the
LEVEL
control
to
zero;
b)
Turn
the
LOUDNESS
control
to
ten;
c)
With
high
level
orchestral
program
material
being
fed
to the
amplifier
from
your
phonograph
or
tuner,
advance
the
LEVEL
control
set-
ting
until a
relatively
loud
listening
level
Is
obtained,
d)
Turn
down
the
LOUDNESS
control
until
your
normal
listening
level
Is obtained
with
the
LEVEL
control
set
as
just
described.
Proper
loudness
compensation
should
now
be
obtained
at
any
listening
level
adjusted
to
with
the
LOUDNESS
control
. The
same
reference
LEVEL
control
setting
will
be
suitable
for
both
phonograph
and
tuner
list-
ening
If
the
volume
control
of
the
tuner
has been
adjusted
as
described
In
the
"High
Level
Inputs"
sub-section
of
the
"Electrical
Connections"
section.
When
selecting
Inputs
which
do
not
have level
ad|usts,
such
as
tv
or
a
crystal
cartridge
connected
to
the AUX.
Input,
It may
be
desir-
able
to
set
the
LEVEL
control
to
zero
beforehand and
then
bring
up
the
LEVEL
control
to obtain
the
desired
list-
ening
level
to
avoid
blasting.
Note
that
the
LEVEL
con-
trols
affects
the
output
to
tape
recorder
available
at
the
TAPE
OUT
jack
but
that
the
LOUDNESS
control
has
no
affect
on
this
output.
BASS
CONTROL:
The
plus
sign
on
the
right
side
of
the
dial
Indicates
that
clockwise
rotation
from
the
mid-point
(0)
Increases
(boosts)
ban
response;
the
minus
sign
on the
left
side
Indicate
that
counter-c
lockwtse
rotation
from
the
mld-potnt
decreases
(cuts)
ban
response.
There
Is no
In-
teraction
with
the
TREBLE
control.
Start all
adjustments
with
this
control
set
at
the
mid-point
(0^
which
Is called
the
"flat"
position
since
ban
response
Is
neither
cut
nor
boosted
at
this
setting.
This
control
does
affect
theout-
put
to a
tape
recorder
from
the
TAPE
OUT
jack
to
permit
"touching
up" of
the
record
equalization
or
reducing
the
effect
of
low
frequency
disturbances
when
recording
on
tape.
Set
It at
zero
If
no
effect
during
recording
Is de-
sired.
e
TREBLE
CONTROL:
The
plus
sign
on the
right
side
of
the
dial
indicates
that
clockwise
rotation
from
the
mid-point
(0)
Increases
(boosts)
treble
response;
the
minus
sign
on
the
left
side
Indicates
that
counter-clockwise
rotation
from
»hs
mid-point
decreases
(cuts)
treble
response.
There
Is
no
Interaction
with
the
BASS
control.
Start
all
adjust-
ments
with
this
control
set at
the
mtd-potnt
(0),
which
Is
called
the
"flat"
position
since
treble
response
Is
neither
cut
nor
boosted
at
this
position.
This
control
does affect
the
output
to
a
tape
recorder
from
the
TAPE
OUT
jack
to
permit
"touching
up" of
the
record
equalization
or
reduc-
ing
the
effect
of
high
frequency
disturbances
when
record-
ing
to
tape.
Set
It
at
zero
If
ho
effect
during
recording
Is
desired.
LISTENING
TO
TUNERS,
TV,
TAPE
RECORDERS:
With
the
SELECTOR
switch
set at
TUNER,
TV,
TAPE
or
AUX-
ILIARY,
the
corresponding
high
level
Input
from
a
radio
tuner,
tv,
tape
recorder,
second
tuner
or
crystal
cartridge
will
feed
through
the
amplifier.
Adjustmentof
the
volume
control
on
each
source
Is
discussed
In
the
"Electrical
Con-
nections"
section
under
"High
Level
Inputs”
and
again
under
"Lever
&
Loudness
Control"
In
this
section.
MAKING
RECORDINGS:
Tape,
wire,
or
disc
recordings
'"ay
be
made
by
connecting
the
recorder
to
the
TAPE
OUTPUT
jack.
See
"TAPE
OUTPUT"
under
ELECTRICAL
CONNECTIONS"
and
the
"BASS
CONTROL"
and
"TRE-
BLE
CONTROL”
operating
Instructions.
With
the
output
of
the
recorder
connected
to
the
"TAPE
INPUT"
jack,
turning
the
SELECTOR
switch
to
TAPE
readies
the
ampli-
fier
for
playback
of
the
recording.
RECORD
EQUALIZATION
SELECTION
Recordsare
made
with
boosted
volume
In
the
treble
range
to
mask
surface
noise
and
reduced
volume
In the
bass
range
to
conserve
groove
space
and
reduce
distortion.
As
there
was
no
universally
accepted
standard
of
treble
boost
and
bass
cut
In
recording
before
Spring
1954,
re-
cords
of
which
the
masters
were
made
before
this date
may
require
any
one
of
several
different
equalizations